Python - mysqlDB，sqlite 结果作为字典

Question

当我做一些事情时，

sqlite.cursor.execute("SELECT * FROM foo")
result = sqlite.cursor.fetchone()

我认为必须记住列似乎能够取出它们的顺序，例如

result[0] is id
result[1] is first_name

有没有办法返回字典？所以我可以只使用 result['id'] 或类似的？

编号列的问题是，如果您编写代码然后插入一列，您可能必须更改代码，例如first_name的result[1]现在可能是date_joined，因此必须更新所有代码...

Answer 1

import MySQLdb
dbConn = MySQLdb.connect(host='xyz', user='xyz', passwd='xyz', db='xyz')
dictCursor = dbConn.cursor(MySQLdb.cursors.DictCursor)
dictCursor.execute("SELECT a,b,c FROM table_xyz")
resultSet = dictCursor.fetchall()
for row in resultSet:
    print row['a']
dictCursor.close
dbConn.close()

Answer 2

在 mysqlDB 中执行此操作，只需将以下内容添加到 connect 函数调用中

cursorclass = MySQLdb.cursors.DictCursor

Answer 3

你可以很容易地做到这一点。对于 SQLite：my_connection.row_factory = sqlite3.Row

查看 python 文档：http://docs.python.org/library/sqlite3.html#accessing-columns-by-name-instead-of-by-index< /a>

更新：

Python 2.6.1 (r261:67515, Feb 11 2010, 00:51:29) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sqlite3
>>> conn = sqlite3.connect(':memory:')
>>> conn.row_factory = sqlite3.Row
>>> c = conn.cursor()
>>> c.execute('create table test (col1,col2)')
<sqlite3.Cursor object at 0x1004bb298>
>>> c.execute("insert into test values (1,'foo')")
<sqlite3.Cursor object at 0x1004bb298>
>>> c.execute("insert into test values (2,'bar')")
<sqlite3.Cursor object at 0x1004bb298>
>>> for i in c.execute('select * from test'): print i['col1'], i['col2']
... 
1 foo
2 bar

Answer 4

David Beazley 在他的 Python Essential Reference 中提供了一个很好的示例。
我手头没有这本书，但我认为他的例子是这样的：

def dict_gen(curs):
    ''' From Python Essential Reference by David Beazley
    '''
    import itertools
    field_names = [d[0].lower() for d in curs.description]
    while True:
        rows = curs.fetchmany()
        if not rows: return
        for row in rows:
            yield dict(itertools.izip(field_names, row))

示例用法：

>>> import sqlite3
>>> conn = sqlite3.connect(':memory:')
>>> c = conn.cursor()
>>> c.execute('create table test (col1,col2)')
<sqlite3.Cursor object at 0x011A96A0>
>>> c.execute("insert into test values (1,'foo')")
<sqlite3.Cursor object at 0x011A96A0>
>>> c.execute("insert into test values (2,'bar')")
<sqlite3.Cursor object at 0x011A96A0>
# `dict_gen` function code here
>>> [r for r in dict_gen(c.execute('select * from test'))]
[{'col2': u'foo', 'col1': 1}, {'col2': u'bar', 'col1': 2}]

Answer 5

sqlite3.Row 实例可以转换为 dict - 非常方便地将结果转储为 json

>>> csr = conn.cursor()
>>> csr.row_factory = sqlite3.Row
>>> csr.execute('select col1, col2 from test')
>>> json.dumps(dict(result=[dict(r) for r in csr.fetchall()]))